Base station wireless channel sounding

ABSTRACT

An example method may include a processing system of a base station having a processor selecting a blank resource of a time and frequency resource grid of the base station for a transmission of a channel sounding waveform and transmitting the channel sounding waveform via the blank resource. Another example method may include a processing system of a channel sounding receiver receiving at a location, from a base station, a channel sounding waveform via a blank resource of a time and frequency resource grid of the base station, and measuring a channel property at the location based upon the channel sounding waveform.

The present disclosure relates generally to wireless channelmeasurements, and more particularly to devices, non-transitory computerreadable media, and methods for channel sounding via an in-service basestation.

BACKGROUND

The spatial, temporal and frequency characterization of the wirelesschannel in various environments is called “channel characterization.”The characterization provides a set of parameters which fully explainthe medium's behavior in various scenarios. A wireless channel sounderis a device for measuring wireless channel related parameters such ascomplex impulse response, path loss, received signal strength (RSS),excess delay, or root-mean-square (RMS) delay spread, Doppler spread,fade rate, angle of arrival (AoA) and/or angle of departure (AoD),shadow fading, cross-polarization ratios, and the like as experienced bya user equipment or base station. In one implementation, a wirelesschannel sounder may utilize a directional antenna. For instance, tomeasure AoA using a directional antenna, the antenna may be turned inincremental steps to measure the RSS. The AoA is recorded where the RSSis at a maximum.

SUMMARY

In one example, the present disclosure discloses a method,computer-readable medium, and device for channel sounding via anin-service base station. For example, a method may include a processingsystem of a base station having a processor selecting a blank resourceof a time and frequency resource grid of the base station for atransmission of a channel sounding waveform and transmitting the channelsounding waveform via the blank resource.

In another example, the present disclosure discloses a method,computer-readable medium, and device for channel sounding via anin-service base station. For example, a method may include a processingsystem of a channel sounding receiver having a processor receiving at alocation, from a base station, a channel sounding waveform via a blankresource of the time and frequency resource grid of the base station,and measuring a channel property at the location based upon the channelsounding waveform that is received.

BRIEF DESCRIPTION OF THE DRAWINGS

The teachings of the present disclosure can be readily understood byconsidering the following detailed description in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a block diagram of an example system, in accordancewith the present disclosure;

FIG. 2 illustrates a flowchart of a first example method for channelsounding via an in-service base station;

FIG. 3 illustrates a flowchart of a second example method for channelsounding via an in-service base station;

FIG. 4 illustrates a flowchart of a third example method for channelsounding via an in-service base station;

FIG. 5 illustrates a flowchart of a fourth example method for channelsounding via an in-service base station;

FIG. 6 illustrates a flowchart of a fifth example method for channelsounding via an in-service base station;

FIG. 7 illustrates a flowchart of a sixth example method for channelsounding via an in-service base station;

FIG. 8 illustrates a flowchart of a seventh example method for channelsounding via an in-service base station; and

FIG. 9 illustrates an example of a computing device, or computingsystem, specifically programmed to perform the steps, functions, blocks,and/or operations described herein.

To facilitate understanding, similar reference numerals have been used,where possible, to designate elements that are common to the figures.

DETAILED DESCRIPTION

The present disclosure broadly discloses methods, computer-readablemedia, and devices for channel sounding via an in-service base station.For instance, the availability of millimeter wave spectrum for 3rdGeneration Partnership Project (3GPP) 5G deployments gives rise to manyopportunities for telecommunications services. Traditional cellularwireless communications networks, however, have not operated in thesebands.

In general, a wireless channel sounding system may comprise atransmitter and a receiver for measuring wireless channel relatedparameters such as a complex impulse response of the wireless channel, apath loss, an excess delay, a root-mean-square (RMS) delay spread, aDoppler spread, a fade rate, an angle of arrival (AoA) or angle ofdeparture (AoD), a shadow fading, a cross-polarization ratio, and thelike as experienced by a user equipment or base station. Themeasurements of the wireless channel related parameters under a varietyof test conditions enable the modeling of the behavior for these channelparameters under different scenarios and conditions, as well as thesimulation and prediction of the performance of a base station or a userequipment under such scenarios and conditions. Thus, modeling of thesewireless channel related parameters and using them in end-to-end networksimulators can guide in mapping out the details of where and how toplace transmitters and receivers in a network for the best mobileperformance and experience.

For instance, in one example, a channel sounding system receiver maymeasure AoA using a directional antenna. The antenna may be turned inincremental steps to measure the received signal strength (RSS). The AoAis recorded where the RSS is maximum. More advanced channel soundingsystem receivers may determine AoA by calculating a phase differencebetween channel sounding waveforms received at antenna elements atdifferent positions within a receiver array, and mapping the phasedifference(s) to the incident direction of the channel soundingwaveforms. Since the phase of a received signal is generally more stablethan the received signal strength (RSS), AoA estimation using phasedifference calculations can achieve higher accuracy than RSS-basedlocalization approaches. Existing single-input single-output (SISO)channel sounding systems, such as those using directional antennareceivers, may be slow in performing measurements at least for certainchannel parameters, may not allow for real-time monitoring of theparameters of interest, and may also be difficult to modify or may beunmodifiable to perform other types of measurements.

In a first example, a channel sounding system is described that uses thetransceivers and baseband processors of a deployed/in-service wirelesscellular communications system for channel sounding by inserting channelsounding waveforms into blank resources of a time-frequency resourcegrid of a base station. The channel sounding waveforms may be based onexisting waveforms that are modified for the purpose of channel soundingor, alternatively, existing or new waveforms may be utilized that aresolely or primarily for the purpose of channel sounding. In either case,in accordance with the first example of the present disclosure, thechannel sounding waveforms are embedded into the base stationtime-frequency grid using forward compatible resources, i.e.,time-frequency resources reserved by the network for future use cases,services, and/or applications. Thus, legacy user equipment will beoblivious to these waveforms, yet their receivers will interpret thewaveforms according to the reserved resources (e.g., rate matching,measurement restrictions, etc.). Alternatively, or in addition, channelsounding waveforms may be embedded in legacy reserved resources of abase station time-frequency grid (e.g., which have subsequently beenreleased and are no longer utilized for the reserved purpose). In oneexample, these reserved resources may be referred to as “blankresources.” Accordingly, channel sounding may be utilized duringinstallation time (e.g., for fixed wireless broadband (FWB)) todetermine the best location and orientation of the customer premiseequipment (CPE). Notably, the present example avoids the need to deploya dedicated channel sounding transmitter at the base station transceiverlocation to sound the channel. Instead, the base station transceiver andbaseband processor itself are used as the transmitter.

In one example, the base station transceiver inserts channel soundingwaveforms into the time-frequency grid, e.g., a 5G “new radio” (NR)waveform, and uses the aforementioned reserved resources to inform theUEs that coexist in the network with the channel sounder receiver aboutthe characterization parameters of the channel sounding waveform, suchas the associated rate matching behavior and/or measurementrestrictions. For instance, in one example a primary synchronizationsignal (PSS) of a synchronization signaling (SS) block is extended infrequency to create a wideband signal without changing the narrowbandpart of the PSS which a UE would expect (e.g., if the UE is operatingaccording to 5G or similar wireless communications standard thatspecifies a narrowband PSS).

In the case of time domain processing, in one example the channelsounding waveform occupies a blank resource of the time-frequency gridbut does not have any kind of alignment with the grid. By way of exampleand without any limitation, a Zadoff-Chu (ZC) sequence in the timedomain may be used for channel sounding. In yet another example, in thecase of frequency domain processing, the sounding signal may be insertedbefore an inverse Fast Fourier Transform (iFFT) stage in thetransmitter. In either case, the receiver processing can be done in thetime domain or frequency domain. In the latter case, however, thechannel sounding waveform may be aligned with the frequency sub-carriersof the time-frequency grid.

In addition to the indication of the configuration of the blank/reservedresources, a channel sounding receiver may be configured with a copy ofthe channel sounding waveform/sequence which will be transmitted in asubset of the blank/reserved resources. The channel sounding receivermay also be configured with other characterization parameters, such as awaveform/sequence indication, timing indication (e.g., periodicity,offset, and the like), and frequency location (e.g. sub-band index, gridalignment, transmission bandwidth, and so forth). These parameters maybe provided by higher layer signaling (e.g., at the radio resourcecontrol (RRC) layer), via pre-configuration, or at the applicationlayer.

In another example, a channel sounder may request an “on-demand”configuration of the blank/reserved resources and corresponding channelsounding waveform/sequence transmission. Thus, the network may conserveresources and mitigate potential sources of interference for other userdata by avoiding transmission of the channel sounding waveform/sequencesunless a channel sounder is present and actively taking measurements.This indication from the channel sounder may be performed as part of ascheduling request message, other higher layer signaling, or at theapplication layer, and may include a request for transmission of thechannel sounding waveform/sequence and corresponding characterizationparameters such as transmission duration, periodicity, bandwidth,transmission power, and so forth.

In a second example, a channel sounding system may use the transceiversand baseband processors of a deployed/in-service wireless cellularcommunications system for channel sounding using standardized waveforms.In particular, the channel sounding is based on waveforms that arealready available from other procedures, such as those fortime/frequency synchronization, phase tracking, positioning estimation,and channel state information estimation. Like the first example, thesecond example of the present disclosure allows channel sounding to beused during installation time (e.g., for a fixed wireless broadband(FWB) deployment) to determine the best location and orientation of thecustomer premise equipment (CPE). The second example also obviates theneed to install a channel sounding transmitter at the base stationtransceiver location to sound the channel. Instead, the base stationtransceiver and baseband processor itself can be used as thetransmitter. However, in contrast to the first example, the secondexample utilizes existing waveforms for channel sounding, therebyminimizing the implementation and testing effort.

To illustrate, in one example, the channel sounding may be based uponthe synchronization signal (SS) of the time-frequency grid of a basestation, e.g., a “new radio” NR synchronization signal (SS), which maycontain a primary synchronization signal (PSS), a secondarysynchronization signal (SSS), a physical broadcast channel (PBCH), and adownlink modulation reference signal (DMRS), to measure one or morechannel properties, or parameters, that characterize the channel. Sincethe synchronization signal is a narrowband signal (e.g., 40 MHz asopposed to 1 GHz), certain channel properties such as path loss,material loss, angular spread, and Doppler spread may be more easilymeasured. In one example, the measurements of channel properties may bederived from multiple signals within the SS block. The time/frequencylocation of the SS block within the time-frequency grid of the basestation may be blindly detected by a channel sounder as part of aninitial access procedure, or may be provided by higher layer signaling,such as at the radio resource control (RRC) layer, by pre-configuration,by the application layer, etc. Notably, channel sounding based upon thesynchronization signaling (SS) block does not require the channelsounder (or “channel sounding receiver”) to implement the full physicallayer specification (e.g., for 5G NR deployment), but only the aspectsof the initial access procedure pertaining to synchronization signaldetection and measurement. This allows the channel sounder to performthe channel sounding measurements of the channel properties withouttransmitter capability.

In another example, channel sounding may be based upon one or morereference signals, such as a channel state information (CSI) referencesignal (RS). In other words, the CSI-RS of a deployed/in-service basestation/cell site may be used to measure channel properties thatcharacterize the channel. When used for channel sounding in accordancewith the present disclosure, the CSI-RS waveform/sequence may bereferred to as a channel sounding waveform. Using CSI-RS allows for MIMO(e.g., multi-port) and wideband measurements (e.g., delay spread). Moreprecisely, for CSI measurement, a base station (e.g., a “gNodeB” or“gNB” in emerging 5G terminology) may typically select a transmit beamthat is best suited for the receiver. However, for the purposes ofchannel sounding, the CSI-RS may instead be beam swept at the basestation/cell site transmitter. In this regard, it should be noted thatin one example, beam sweeping of the CSI-RS may be made part of apermitted beam management procedure defined in the specification of theconsidered wireless cellular communications standard (e.g., 3GPP 5G).If, however, existing or emerging standards effectively prevent theCSI-RS from being beam swept, in another example, the base stationtransmitter may configure reserved resources and transmit beam sweptCSI-RS for sounding purposes in the configured reserved resources. Forinstance, reserved resources are described above in connection with thefirst example of the present disclosure and may comprise blank resourcesthat are set aside for future and/or legacy compatibility.

In one example, when CSI-RS is used for channel sounding, the CSI-RSdensity can be increased by configuring multiple CSI-RS resources, allof which may use the same sequence. In this example, the channelsounding receiver can aggregate the CSI-RS from multiple resources toobtain processing gain. Moreover, in order to establish over-the-air(OTA) calibration between the channel sounding transmitter (e.g., a basestation) and channel sounding receiver, multiple CSI-RS resources can beaggregated to form per-antenna-element antenna ports, e.g., using aspecial analog precoder in the radio frequency (RF) domain. In such anexample, the channel sounding receiver can use these per antenna elementantenna ports to estimate the phase offset between antenna elements.

In yet another example, channel sounding may be based upon positioningreference signals (PRS) that are transmitted by a base station. PRSs aretypically received by a UE from several base stations, and are used todetermine its position based upon time differences in the receipt of theseveral PRSs relative to reference timing signal. However, in accordancewith the second example of the present disclosure, the PRS may be usedto measure channel properties that characterize the channel. When usedfor channel sounding in accordance with the present disclosure, the PRSwaveform/sequence may be referred to as a channel sounding waveform.

In a third example, a channel sounding system may use the transceiversand baseband processors of a deployed/in-service wireless cellularcommunications system for channel sounding using non-randompredetermined bit sequences. In particular, a non-random/pseudo-randompredetermined bit sequence is transmitted on a shared data channel andthe resulting waveform generated from the pseudo-random bit sequence(“data”) is used for channel sounding. The bit sequence is predeterminedinsofar as it is selected in advance (e.g., by the base station) or thechannel sounding receiver. Accordingly, the resulting waveform may bereferred to as a “channel sounding waveform.” Like the first and secondexamples, the third example of the present disclosure allows channelsounding to be used during installation time (e.g., for a fixed wirelessbroadband (FWB) deployment) to determine the best location andorientation of the customer premise equipment (CPE). The third examplealso obviates the need to install a channel sounding transmitter at thebase station transceiver location to sound the channel. Instead, thebase station transceiver and baseband processor itself can be used asthe transmitter.

In one example, the pre-determined bit sequence for a channel soundingwaveform is inserted in the bit domain as a medium access control (MAC)transport block, while the physical layer processing remains inaccordance with the wireless cellular communications standard that isimplemented by the base station transmitter. To illustrate, thegenerating and transmitting of a channel sounding waveform may proceedas follows. First, the base station MAC scheduler may allocate theentire available transmission bandwidth to the physical data sharedchannel (PDSCH) of a channel sounding receiver. In one example, the MACscheduler may also set the transmit rank of said PDSCH to 1. Inaddition, in one example, the MAC scheduler may also set a modulationcoding scheme (MCS) to lowest available MCS of the PDSCH. For example,the lowest MCS level may be associated with binary phase shift keying(BPSK), quadrature phase shift keying (QPSK), or other modulationschemes are possible for association with the lowest MCS level.Alternatively, the MAC scheduler may not choose the lowest MCS level butanother MCS level. In still another example, the MAC scheduler mayassign a transmission scheme not associated with a precoding matrixindicator (PMI) with the PDSCH, e.g., one based on pre-coder cycling.

The MAC scheduler may next set the payload (data) part of the MACprotocol data unit (PDU) to a predetermined bit sequence. Thepredetermined bit sequence (e.g., a pseudo-random set of bits)effectively creates the transport block for that transmission timeinterval (TTI). It should be noted that the transport block bits aretypically not known in advance at the receiver. However, in this case,the transport block bits (the predetermined bit sequence) are known atthe receiver (i.e., the channel sounding receiver). The channel soundingreceiver may also store various parameters associated with thepredetermined bit sequence and/or characterizing the channel soundingwaveform that is generated from the predetermined bit sequence, such as:code rate, redundancy version, modulation level, precoding matrixindicator (PMI), resource mapping, and so forth. Accordingly, in oneexample, the entire PDSCH is a known wideband signal at the channelsounding receiver.

In another example, the base station transmitter sets the payload ordata part of a radio link control (RLC) PDU to a predetermined bitsequence (where the predetermined bit sequence is associated with achannel sounding waveform to be transmitted). In a further example, thebase station transmitter sets the payload or data part of the PacketData Convergence Protocol (PDCP) PDU to a predetermined bit sequence. Instill another example, an OCNS (orthogonal channel noise simulator) atthe base station (e.g., a gNodeB) is used to generate a pre-determinedpseudo-random sequence which is inserted into the physical layer (PHY)processing unit at the transport block level. In this example, the MACat the gNodeB may use the entire bandwidth available for the PDSCH togenerate the predetermined pseudo-random sequence and does not allocateany resources to another user equipment. It should be noted that thepredetermined pseudo-random sequence may be notified in advance to thechannel sounding receiver, e.g., via control signaling.

Other points in the protocol stack where the predetermined bit sequencemay be included as the payload or data part of a PDU or service dataunit (SDU) are also within the scope of the third example. Generally,the higher in the protocol stack of the considered wireless cellularcommunications standard, the easier the example is implementable withinthe confines of the considered wireless cellular communicationsstandard. In another example, the base station (e.g., a gNodeB) usesforward compatible blank resources that are not available to other UEs,and uses these blank resources to generate a wideband signal using theNR physical layer. (Forward compatible black resources are described ingreater detail above in connection with the first example).

In one example, sequence numbers may not be known in advance when thepredetermined bit sequence is included as the payload or data part inhigher layers of the protocol stack. In addition, although the basestation transmitter may insert the predetermined bit sequence atdifferent layers of the protocol stack, the channel sounding receivermay process the received predetermined set of bits at the physical layeras part of the channel sounding measurement procedure without passingthe payload to higher layers in the channel sounding receiver's protocolstack. Thus, the received channel sounding waveform may be directlyprocessed within the physical layer, or may be stored/transported forprocessing in real-time or at a later time by the channel soundingreceiver or by a different device or system.

In one embodiment, the channel sounding receiver may be preconfiguredwith the predetermined bit or may be provided with the predetermined bitsequence and corresponding characterization parameters for channelmeasurement based on higher layer signaling (e.g., at the RRC layer orapplication layer). The channel sounding receiver may be provided withthe exact bits of the sequence or one or more initialization parameters,such as a pseudo-random sequence seed which may be a function of one ormore parameters including system frame number, slot index, symbol index,(virtual) cell identifier (ID), and/or user equipment (UE) ID (where theUE is the channel sounder receiver). In another example, the channelsounding receiver may be configured with a pattern or periodicityindicating the transmission of the channel sounding waveform relative tothe system timing (e.g., a radio frame). This timing indication mayinclude a periodicity, offset expressed in absolute time (e.g., secondsor milliseconds) or scheduling units (e.g., slots or symbols). In oneexample, the radio frame may be in accordance with the 5G “new radio”(NR) radio frame.

Additionally, if multiple frequency sub-bands or carriers are configuredfor the channel sounding receiver to receive a channel soundingwaveform, or channel sounding waveforms, the configuration may includeinformation regarding the associated frequency location(s) (or hoppingpattern) associated with a given time location. Accordingly, the channelsounding receiver may attempt to detect the channel sounding signal atthe configured locations and may switch off components of the receiverchain between channel sounding waveform transmission instances, or maycontinue monitoring downlink radio frames for normal control/datachannel transmissions.

In another example, the channel sounding receiver may operate without acopy and/or characterization parameters of the predetermined bitsequence and/or the channel sounding waveform that is generatedtherefrom. Instead, the channel sounding receiver may attempt to blindlydetect the channel sounding waveform and upon successfully processing atransport block matching the preconfigured sounding signalcharacteristics (e.g., after a cyclic redundancy check (CRC) passdetection), proceed to process the sequence as part of its configuredchannel sounding measurement procedure.

The following relates to all of the first, second, and third examplesdescribed above. In one example, for purposes of calibration and accountfor unknown parameters, such as power level, antenna gain, and beampattern, for each beam sweep the channel sounding receiver may be placednear the base station transmitter/antennas in several line-of-sight(LOS) places. By sounding the channel in a three-dimensional(physical/spatial) grid up close to the transmitting antennas, thechannel sounding receiver may collect a spatially dense sample ofchannel property measurements related to channel. This densethree-dimensional information can then be used to reverse engineervarious unknown parameters, such as the power, antenna gain, beampattern of the beam sweep, and so forth.

For all of the first, second, and third examples described above, thechannel sounder, or channel sounding receiver, may comprise a userequipment (UE) that is equipped to operate according to thespecification of the considered wireless cellular communicationsstandard (e.g., 5G MIMO and/or millimeter wave). However, the UE may beconfigured with additional capabilities, including the ability to beamsweep the receive beam, the ability to log the multiple-inputmultiple-output (MIMO) channel response, and the ability to use the MIMOchannel response to derive small scale and large scale parameters(channel property measurements) that characterize the channel. Inaddition, in one example the sounder receiver may comprise a system thatincludes a user equipment (UE) for communications with the base stationtransmitter and a channel sounder receiver unit. For example, the UE maybe implemented via a universal serial bus (USB) dongle that allows achannel sounder receiver software to run as an application on aprocessing unit, e.g., of a computer that connects via the (USB)interface with a UE modem on the USB dongle.

With respect to all of the first, second, and third examples describedabove, the channel sounding receiver may exchange control informationwith the base station transmitter that is used for channel sounding. Inone example, the UE functions of the channel sounding receiver couldeither be of the same standard/release as the cellular base stationtransmitter that acts as the channel sounding transmitter or of adifferent standard/release (e.g., 3GPP 4G/Long Term Evolution (LTE), 5Gnew radio (NR), or other set(s) of specifications). For example, in caseof the UE being according to the specification of the consideredwireless cellular communications standard (e.g., 5G NR) but with someadditional capabilities, both the UE and the cellular base stationtransmitter that acts as sounder could be implemented according to theNR specifications notwithstanding the additional capabilities of thesounder transmitter at the base station side and the sounder receiver atthe UE side. Alternatively, the base station could be implementedaccording to the NR specifications with additional capabilities to actas sounder transmitter. However, the base station may exchange thecontrol information with the channel sounding receiver via an LTE airinterface. Notably, using the LTE air interface for the controlsignaling may increase the range of the channel sounding capabilitybeyond what would be possible if it was solely operating in millimeterwave spectrum using NR technology.

With respect to all three of the examples above, the channel soundingreceiver may not implement the entire protocol stack according to thespecification of the wireless cellular communications standardassociated with the channel for which channel properties are to bemeasured (e.g., 5G NR). For example, the channel sounding receiver mayonly implement or utilize the subset of functions that is required forthe purpose of channel sounding. In one example, the channel soundingreceiver may control the base station transmitter, e.g., by providingchannel sounding waveforms, instructions as to when and how to transmitchannel sounding waveforms, and so forth. However, in another example,the base station that is used for channel sounding may control thechannel sounding receiver. In addition, in one example the roles of thebase station and channel sounding can be reversed. In other words, achannel sounder receiver can also be integrated with a base station, inwhich case the channel sounding transmitter is integrated with a userequipment. In one example, the role of the base station can beimplemented in a second UE. In other words, channel sounding receivercan be one UE and channel sounding transmitter can be another UE. Inthis case, a direct UE-to-UE (e.g., sidelink) is used for channelsounding.

Although examples of the present disclosure are applicable to a widerange of frequency bands, in one example, the present disclosure mayrelate to centimeter and millimeter wave systems. For instance, for allof the examples herein, the considered wireless cellular communicationsstandard can be the Third Generation Project (3GPP) New Radio (NR) radioaccess technology. For the embodiments herein, the base station can be agNB or gNodeB or base station of a 5G-RAN (fifth generation radio accessnetwork). It should be noted that for illustrative purposes, variousbase station systems are described herein in connection with particularquantities or values. However, base station systems of the presentdisclosure may include different quantities of various components,and/or operating parameters which may have any number of differentvalues. For instance, a base station system may have a different numbertransmit antennas, may have antennas with different beamwidths, mayutilize different frequencies, may utilize different transmit powers,and so forth. In addition, a base station system may include a differentnumber of antenna sector units covering a same or a different range inazimuth and/or elevation, may have sectors with different coverages, mayhave a different number of antenna elements per sector, may have adifferent desired SNRs, may utilize a fewer number of samples perantenna for a different averaging gain, and so forth. These and otheraspects of the present disclosure are discussed in greater detail belowin connection with the examples of FIGS. 1-8.

To better understand the present disclosure, FIG. 1 illustrates anexample network, or system 100 in which examples of the presentdisclosure for channel sounding via an in-service base station mayoperate. In one example, the system 100 includes a telecommunicationservice provider network 170. The telecommunication service providernetwork 170 may comprise a cellular network 101 (e.g., a 4G/Long TermEvolution (LTE) network, a 4G/5G hybrid network, or the like), a servicenetwork 140, and a core network, e.g., an IP Multimedia Subsystem (IMS)core network 115. The system 100 may further include other networks 180connected to the telecommunication service provider network 105. FIG. 1also illustrates various mobile endpoint devices 116 and 117, e.g., userequipment or user endpoints (UE). The mobile endpoint devices UE 116 and117 may each comprise a cellular telephone, a smartphone, a tabletcomputing device, a laptop computer, a pair of computing glasses, awireless enabled wristwatch, or any other cellular-capable mobiletelephony and computing device (broadly, “mobile endpoint devices”).

In one example, the cellular network 101 comprises an access network 103and a core network, Evolved Packet Core (EPC) network 105. In oneexample, the access network 103 comprises a cloud RAN. For instance, acloud RAN is part of the 3rd Generation Partnership Project (3GPP) 5Gspecifications for mobile networks. As part of the migration of cellularnetworks towards 5G, a cloud RAN may be coupled to an EPC network untilnew cellular core networks are deployed in accordance with 5Gspecifications. In one example, access network 103 may include cellsites 111 and 112 and a baseband unit (BBU) pool 114. In a cloud RAN,radio frequency (RF) components, referred to as remote radio heads(RRHs), may be deployed remotely from baseband units, e.g., atop cellsite masts, buildings, and so forth. In one example, the BBU pool 114may be located at distances as far as 20-80 kilometers or more away fromthe antennas/remote radio heads of cell sites 111 and 112 that areserviced by the BBU pool 114. It should also be noted in accordance withefforts to migrate to 5G networks, cell sites may be deployed with newantenna and radio infrastructures such as multiple input multiple output(MIMO) antennas, and millimeter wave antennas. In this regard, a cell,e.g., the footprint or coverage area of a cell site, may in someinstances be smaller than the coverage provided by NodeBs or eNodeBs of3G-4G RAN infrastructure. For example, the coverage of a cell siteutilizing one or more millimeter wave antennas may be 1000 feet or less.

Although cloud RAN infrastructure may include distributed RRHs andcentralized baseband units, a heterogeneous network may include cellsites where RRH and BBU components remain co-located at the cell site.For instance, cell site 113 may include RRH and BBU components. Thus,cell site 113 may comprise a self-contained “base station.” With regardto cell sites 111 and 112, the “base stations” may comprise RRHs at cellsites 111 and 112 coupled with respective baseband units of BBU pool114.

In accordance with the present disclosure any one or more of cell sites111-113 may be deployed with antenna and radio infrastructures,including multiple input multiple output (MIMO) and millimeter waveantennas. Furthermore, in accordance with the present disclosure, a basestation (e.g., cell sites 111-113 and/or baseband units within BBU pool114) may comprise all or a portion of a computing device or system, suchas computing system 900, and/or processing system 902 as described inconnection with FIG. 9 below, and may be configured to provide one ormore functions for channel sounding via an in-service base station, andfor performing various other operations in accordance with the presentdisclosure. For instance, cell sites 111-113 and/or baseband unitswithin BBU pool 114 may be configured to perform functions such as thosedescribed below in connection with the example methods of FIGS. 2-8. Forinstance, cell site 113 may receive a notification of a presence ofchannel sounder 120, may transmit to or receive from the channel sounder120 test channel sounding waveforms and/or characterization parameters,including timing information, signal bandwidth, signal power,sub-carrier identification, and the like, may transmit the channelsounding waveforms via the “channel” for which the channel property orproperties is/are to be measured, and so forth.

In addition, it should be noted that as used herein, the terms“configure,” and “reconfigure” may refer to programming or loading aprocessing system with computer-readable/computer-executableinstructions, code, and/or programs, e.g., in a distributed ornon-distributed memory, which when executed by a processor, orprocessors, of the processing system within a same device or withindistributed devices, may cause the processing system to perform variousfunctions. Such terms may also encompass providing variables, datavalues, tables, objects, or other data structures or the like which maycause a processing system executing computer-readable instructions,code, and/or programs to function differently depending upon the valuesof the variables or other data structures that are provided. As referredto herein a “processing system” may comprise a computing deviceincluding one or more processors, or cores (e.g., as illustrated in FIG.6 and discussed below) or multiple computing devices collectivelyconfigured to perform various steps, functions, and/or operations inaccordance with the present disclosure.

In one example, the channel sounder 120 may be used to determinemeasures of various wireless channel parameters (broadly “channelsounding”). In one example, channel sounder 120 may comprise a userequipment, e.g., a mobile endpoint device comprising a cellulartelephone, a smartphone, a tablet computing device, a laptop computer,or any other cellular-capable mobile telephony and computing devices. Inone example, channel sounder 120 may comprise a dedicated channelsounding device.

In one example, the channel sounder 120 may be used to receive channelsounding waveforms that are transmitted in an environment, where thechannel sounding waveforms, as received, may be used to calculate ordetermine the measures of various wireless channel parameters such as:multipath amplitude(s), phase(s), direction(s) or angle(s) of arrival, apath loss, an excess delay, a RMS delay spread, a Doppler spread, a faderate, a complex impulse response of the wireless channel, and so forth.

In one example, the channel sounder 120 includes a plurality of antennasector units that may be activated and deactivated according to aschedule or otherwise synchronized to the transmission of channelsounding waveforms. In one example, baseband converters may receiveradio frequency (RF) signals from the antenna sector units and convertthe signals into baseband signals. Digital sampling units may convertthe baseband signals into digital representations of the channelsounding waveforms that are received via the respective antenna sectorunits. For instance, the digital sampling units may oversample theanalog baseband signals at a sampling interval under the control oftiming signals from a clock circuit to create the digitalrepresentations of the channel sounding waveforms.

The digital sampling units may output the digital representations of thechannel sounding waveforms to a processor unit that is configured toperform various operations for determining measures of wireless channelparameters, as described herein. For instance, the channel sounder 120may calculate, based upon the digital representations of the channelsounding waveforms, a phase difference between channel soundingwaveforms received via respective antennas. The processor unit mayfurther determine an angle of arrival (AoA) based upon the antennapositions and the phase difference. In one example, the channel sounder120 may receive a reference copy or copies of the channel soundingwaveforms(s) and/or a set of parameters characterizing the channelsounding waveforms, from the transmitter (e.g., cell site 113).Accordingly, the channel sounder 120 may determine acarrier-to-interference (CIR) ratio by comparing a sequence received viaone of the antenna sector units with a reference copy. Alternatively, orin addition, the channel sounder 120 may calculate a path loss, anexcess delay, a RMS delay spread, a fade rate, a Doppler spread, acomplex impulse response, or the like, from the digital representationsof the channel sounding waveforms.

In one example, the channel sounder 120 may perform further functions,including communicating with a transmitter-side device (e.g., cell site113) to coordinate the timing of the transmission of the channelsounding waveforms with activations and deactivations of antenna sectorunits to receive reference copies of channel sounding waveforms that aretransmitted, and so forth. For instance, the channel sounder 120 maymaintain a communication link, such as via control signalingcommunications or an out-of band wireless link (e.g., using a differentset of antennas and a different RF communication band than the antennasector units that are used for channel sounding/channel propertymeasurements in accordance with the present disclosure) to communicatewith cell site 113.

In one example, the channel sounder 120 may comprise all or a portion ofa computing device or system, such as computing system 900, and/orprocessing system 902 as described in connection with FIG. 9 below, andmay be configured to provide one or more functions for channel soundingvia an in-service base station, and for performing various otheroperations in accordance with the present disclosure. For instance,channel sounder 120 may be configured to perform functions such as thosedescribed below in connection with the example methods of FIGS. 2-8. Inthis regard, it should be noted that in one example, channel soundingreceiver may control a channel sounding via an in-service base station,e.g., by instructing cell site 113 or another channel soundingtransmitter to begin transmission of channel sounding waveforms, byproviding test copies and/or parameters characterizing the channelsounding waveforms, including bandwidth, periodicity, and bit sequences,and so forth. In addition, channel sounding receiver may obtain andstore channel property measurements, and may perform additionaloperations based upon the channel property measurements, such asdetermining locations and/or orientations for deployment of customerpremises equipment, e.g., for fixed wireless broadband (FWB), or thelike. However, in another example, channel sounder 120 may be controlledby another device, such as cell site 113. For instance, channel sounder120 may receive test copies or characterization parameters of channelsounding waveforms from cell site 113, may measure channel properties inaccordance with the test copies or characterization parameters, and maytransmit the measured channel properties to cell site 113. For example,cell site 113 or another component of telecommunication network 170 maythen aggregate channel property measures, and may determine locationsand/or orientations for deployment of customer premises equipment, e.g.,for fixed wireless broadband (FWB), or the like, based upon the channelproperty measures, and so forth.

In one example, the EPC network 105 provides various functions thatsupport wireless services in the LTE environment. In one example, EPCnetwork 105 is an Internet Protocol (IP) packet core network thatsupports both real-time and non-real-time service delivery across a LTEnetwork, e.g., as specified by the 3GPP standards. In one example, allcell sites in the access network 103 are in communication with the EPCnetwork 105 via baseband units in BBU pool 114. In operation, mobileendpoint device UE 116 may access wireless services via the cell site111 and mobile endpoint device UE 117 may access wireless services viathe cell site 112 located in the access network 103. It should be notedthat any number of cell sites can be deployed in access network. In oneillustrative example, the access network 103 may comprise one or morecell sites.

In EPC network 105, network devices such as Mobility Management Entity(MME) 107 and Serving Gateway (SGW) 108 support various functions aspart of the cellular network 101. For example, MME 107 is the controlnode for the LTE access network. In one embodiment, MME 107 isresponsible for UE (User Equipment) tracking and paging (e.g., such asretransmissions), bearer activation and deactivation process, selectionof the SGW, and authentication of a user. In one embodiment, SGW 108routes and forwards user data packets, while also acting as the mobilityanchor for the user plane during inter-cell handovers and as the anchorfor mobility between LTE and other wireless technologies, such as 2G and3G wireless networks.

In addition, EPC network 105 may comprise a Home Subscriber Server (HSS)109 that contains subscription-related information (e.g., subscriberprofiles), performs authentication and authorization of a wirelessservice user, and provides information about the subscriber's location.The EPC network 105 may also comprise a packet data network (PDN)gateway 110 which serves as a gateway that provides access between theEPC network 105 and various data networks, e.g., service network 140,IMS core network 115, other network(s) 180, and the like. The packetdata network gateway is also referred to as a PDN gateway, a PDN GW or aPGW. In addition, the EPC network 105 may include a Diameter routingagent (DRA) 106, which may be engaged in the proper routing of messagesbetween other elements within EPC network 105, and with other componentsof the system 100, such as a call session control function (CSCF) (notshown) in IMS core network 115. For clarity, the connections between DRA106 and other components of EPC network 105 are omitted from theillustration of FIG. 1.

In one example, service network 140 may comprise one or more devices,such as application server (AS) 145 for providing services tosubscribers, customers, and or users. For example, telecommunicationservice provider network 170 may provide a cloud storage service, webserver hosting, and other services. As such, service network 140 mayrepresent aspects of telecommunication service provider network 170where infrastructure for supporting such services may be deployed. Inone example, AS 145 may comprise all or a portion of a computing deviceor system, such as computing system 900, and/or processing system 902 asdescribed in connection with FIG. 9 below, specifically configured toprovide one or more service functions in accordance with the presentdisclosure, such as a network-based secure data storage for channelsounding records (broadly “channel property measurements”). Forinstance, cell site 113 may collect channel property measurements fromchannel sounder 120 and may forward the channel property measurements toAS 145 for storage. Although a single application server, AS 145, isillustrated in service network 140, it should be understood that servicenetwork 140 may include any number of components to support one or moreservices that may be provided to one or more subscribers, customers, orusers by the telecommunication service provider network 170.

In one example, other networks 180 may represent one or more enterprisenetworks, a circuit switched network (e.g., a public switched telephonenetwork (PSTN)), a cable network, a digital subscriber line (DSL)network, a metropolitan area network (MAN), an Internet service provider(ISP) network, and the like. In one example, the other networks 180 mayinclude different types of networks. In another example, the othernetworks 180 may be the same type of network. In one example, the othernetworks 180 may represent the Internet in general.

In accordance with the present disclosure, any one or more of thecomponents of EPC network 105 may comprise network functionvirtualization infrastructure (NFVI), e.g., SDN host devices (i.e.,physical devices) configured to operate as various virtual networkfunctions (VNFs), such as a virtual MME (vMME), a virtual HHS (vHSS), avirtual serving gateway (vSGW), a virtual packet data network gateway(vPGW), and so forth. For instance, MME 107 may comprise a vMME, SGW 108may comprise a vSGW, and so forth. In this regard, the EPC network 105may be expanded (or contracted) to include more or less components thanthe state of EPC network 105 that is illustrated in FIG. 1. In thisregard, the EPC network 105 may also include a self-optimizingnetwork(SON)/software defined network (SDN) controller 190. In oneexample, SON/SDN controller 190 may function as a self-optimizingnetwork (SON) orchestrator that is responsible for activating anddeactivating, allocating and deallocating, and otherwise managing avariety of network components. For instance, SON/SDN controller 190 mayactivate and deactivate antennas/remote radio heads of cell sites 111and 112, respectively, may allocate and deactivate baseband units in BBUpool 114, and may perform other operations for activating antennas basedupon a location and a movement of a group of mobile endpoint devices, inaccordance with the present disclosure.

In one example, SON/SDN controller 190 may further comprise a SDNcontroller that is responsible for instantiating, configuring, managing,and releasing VNFs. For example, in a SDN architecture, a SDN controllermay instantiate VNFs on shared hardware, e.g., NFVI/host devices/SDNnodes, which may be physically located in various places. In oneexample, the configuring, releasing, and reconfiguring of SDN nodes iscontrolled by the SDN controller, which may store configuration codes,e.g., computer/processor-executable programs, instructions, or the likefor various functions which can be loaded onto an SDN node. In anotherexample, the SDN controller may instruct, or request an SDN node toretrieve appropriate configuration codes from a network-basedrepository, e.g., a storage device, to relieve the SDN controller fromhaving to store and transfer configuration codes for various functionsto the SDN nodes.

In accordance with the present disclosure, SON/SDN controller 190 maytherefore control various components within EPC network 105 and/orwithin access network 103 to support the traffic that is accommodated bythe activation of antennas/remote radio heads of cell sites 111 and 112,respectively and the allocation of baseband units in BBU pool 114. Forinstance, SON/SDN controller 190 (e.g., performing functions of a SONorchestrator) may activate an antenna of cell site 111 and assign abaseband unit in BBU pool 114 when a group of mobile endpoint devices isdetected near the cell site 111. SON/SDN controller 190 (e.g.,performing functions of a SDN controller) may further instantiate VNFsto function as routers, switches, gateways, and the like to ensure thatsufficient backhaul resources are available for the traffic to transitthe access network 103 and/or EPC network 105. In addition, as mentionedabove, any one or more of the DRA 106, MME 107, SGW 108, HSS 109, andPGW 110 may comprise VNFs instantiated on host devices. As such, SON/SDNcontroller 190 may perform similar operations to instantiate, configure,reconfigure, and decommission such components in support of examples ofthe present disclosure for activating antennas based upon a location anda movement of a group of mobile endpoint devices.

In one example, SON/SDN controller 190 may comprise all or a portion ofa computing device or system, such as computing system 900, and/orprocessing system 902 as described in connection with FIG. 9 below, andmay be configured to provide one or more functions to support examplesof the present disclosure for channel sounding via an in-service basestation, and for performing various other operations in accordance withthe present disclosure. For example, SON/SDN controller 190 may ensurethat a cell site 111-113 and/or baseband unit of BBU pool 114 isprovisioned with configuration code which, when executed by a processingsystem of the respective component(s), cause various operations inconnection with the examples of FIGS. 2-8 to be performed. For instance,SON/SDN controller 190 may store such configuration code and provisionthe code to the respective component(s), or may direct the respectivecomponent(s) to obtain the configuration code from another repository.

Accordingly, the SON/SDN controller 190 may be connected directly orindirectly to any one or more network elements of EPC network 105, andof the system 100 in general. Due to the relatively large number ofconnections available between SON/SDN controller 190 and other networkelements, none of the actual links to the application server are shownin FIG. 1. Similarly, intermediate devices and links between DRA 106,MME 107, SGW 108, eNodeBs 111 and 112, PDN gateway 110, and othercomponents of system 100 are also omitted for clarity, such asadditional routers, switches, gateways, and the like.

As further illustrated in FIG. 1, EPC network 105 may further include anapplication server (AS) 130, which may comprise all or a portion of acomputing device or system, such as computing system 900, and/orprocessing system 902 as described in connection with FIG. 9 below, andmay be configured to perform various operations in connection withchannel sounding via an in-service base station, and for performingvarious other operations in accordance with the present disclosure. Forinstance, AS 130 may select channel sounding waveforms to be used forchannel property measurements, may provide the channel soundingwaveforms to base stations for transmission, may provide test copiesand/or characterization parameters of channel sounding waveforms tochannel sounding receivers, such as channel sounder 120, and so forth.In this regard, AS 130 may maintain communications with BBU pool 114,cell sites 111-113, channel sounder 120, and so forth, via PDN gateway110 and SGW 108, for example. AS 130 may also receive channel propertymeasurements from channel sounding receivers via respective basestations, and may perform other operations based upon the channelproperty measurements that are received. For instance, AS 130 may selecta location and/or orientation of a customer premises equipment (CPE),based upon the channel property measurements. For example, channelsounding via cell site 113 and channel sounder 120 may be performed atseveral candidate locations for a CPE, and a location (and/ororientation) with the highest signal to interference and noise ratio(SINR), may be selected. In one example, AS 130 may collect and storechannel property measurements locally, e.g., in an internal or attachedstorage device, or remotely, e.g., in a cloud based data storageinfrastructure, or the like. For instance, AS 130 may store the channelproperty measurements in AS 145 of service network 140, may retrieve thechannel property measurements to calculate a preferred CPE locationand/or orientation, or to perform other operations in accordance withthe present disclosure.

The foregoing description of the system 100 is provided as anillustrative example only. In other words, the example of system 100 ismerely illustrative of one network configuration that is suitable forimplementing embodiments of the present disclosure. As such, otherlogical and/or physical arrangements for the system 100 may beimplemented in accordance with the present disclosure. For example, thesystem 100 may be expanded to include additional networks, such asnetwork operations center (NOC) networks, additional access networks,and so forth. The system 100 may also be expanded to include additionalnetwork elements such as border elements, routers, switches, policyservers, security devices, gateways, a content distribution network(CDN) and the like, without altering the scope of the presentdisclosure. In addition, system 100 may be altered to omit variouselements, substitute elements for devices that perform the same orsimilar functions, combine elements that are illustrated as separatedevices, and/or implement network elements as functions that are spreadacross several devices that operate collectively as the respectivenetwork elements. For instance, in one example, SON/SDN controller 190may be spilt into separate components to operate as a SON orchestratorand a SDN controller, respectively. Similarly, although the SON/SDNcontroller 190 is illustrated as a component of EPC network 105, inanother example SON/SDN controller 190, and/or other network componentsmay be deployed in an IMS core network 115 instead of being deployedwithin the EPC network 105, or in other portions of system 100 that arenot shown, while providing essentially the same functionality.Similarly, functions described herein with respect to AS 130 mayalternatively or additional be provided by AS 145.

It should also be noted that the foregoing is described primarily inconnection with examples where channel sounding is performed withrespect to cell site 113 and channel sounder 120. However, in other,further, and different examples, channel sounding may be performed atcell site 111 or cell site 112. For instance, channel sounder 120 may bedeployed within communication and/or reception range of cell site 111 orcell site 112, and channel sounding waveforms may be transmitted by cellsite 111 or cell site 112, respectively. In addition, although channelsounder 120 comprises a dedicated channel sounding receiver in oneexample, it should be noted that examples of the present disclosure mayalso utilize UE 116, UE 117 or other mobile endpoint devices as achannel sounding receiver. For instance, UE 116 and/or UE 117 mayinclude a MIMO antenna to receive multi-path and/or spatial diversitysignals, a gyroscope and compass to determine orientation(s), and soforth. Thus, in one example, UE 116 and/or UE 117 may comprise all or aportion of a computing device or system, such as computing system 900,and/or processing system 902 as described in connection with FIG. 9below, and may be configured to perform various operations for channelsounding via an in-service base station, and for performing variousother operations in accordance with the present disclosure.

In addition, although aspects of the present disclosure have beendiscussed above in the context of a long term evolution (LTE)-basedwireless network, examples of the present disclosure are not so limited.Thus, the teachings of the present disclosure can be applied to othertypes of wireless networks (e.g., a 2G network, a 3G network, a 5Gnetwork, an integrated network, e.g., including any two or more of 2G-5Ginfrastructure and technologies, and the like), that are suitable foruse in connection with examples of the present disclosure for channelsounding via an in-service base station. For example, as illustrated inFIG. 1, the cellular network 101 may represent a “non-stand alone” (NSA)mode architecture where 5G radio access network components, such as a“new radio” (NR), “gNodeB” (or “gNB”), and so forth are supported by a4G/LTE core network (e.g., a Evolved Packet Core (EPC) network 105).However, in another example, system 100 may instead comprise a 5G“standalone” (SA) mode point-to-point or service-based architecturewhere components and functions of EPC network 105 are replaced by a 5Gcore network, which may include an access and mobility managementfunction (AMF), a user plane function (UPF), a session managementfunction (SMF), a policy control function (PCF), a unified datamanagement function (UDM), an authentication server function (AUSF), anapplication function (AF), a network repository function (NRF), and soon. For instance, in such a network, application server (AS) 130 of FIG.1 may represent an application function (AF) for managing channelsounding via an in-service base station in accordance with variousexamples of the present disclosure. In addition, any one or more of cellsites 111-113 may comprise 2G, 3G, 4G and/or LTE radios, e.g., inaddition to 5G new radio (NR) functionality. For instance, innon-standalone (NSA) mode architecture, LTE radio equipment may continueto be used for cell signaling and management communications, while userdata may rely upon a 5G new radio (NR), including millimeter wavecommunications, for example. Thus, these and other modifications are allcontemplated within the scope of the present disclosure.

FIG. 2 illustrates a flowchart of an example method 200 for channelsounding via an in-service base station, in accordance with the presentdisclosure. In one example, steps, functions and/or operations of themethod 200 may be performed by a device as illustrated in FIG. 1, e.g.,a base station, or any one or more components thereof, such as aprocessing system, a processing system in conjunction with remote radioheads and/or antenna arrays, and so forth. In one example, the steps,functions, or operations of method 200 may be performed by a computingdevice or system 900, and/or a processing system 902 as described inconnection with FIG. 9 below. For instance, the computing device 900 mayrepresent at least a portion of a base station in accordance with thepresent disclosure. For illustrative purposes, the method 200 isdescribed in greater detail below in connection with an exampleperformed by a processing system, such as processing system 902. Themethod 200 begins in step 205 and may proceed to optional step 210,optional step 220, or step 230.

At optional step 210, the processing system (e.g., of a base station)may receive a notification of a presence of the channel soundingreceiver that is ready to measure the channel property. In one example,the notification comprises an instruction to transmit the channelsounding waveform via the blank resource. In one example, theinstruction includes characterization parameters of the channel soundingwaveform. The characterization parameters may comprise at least one of:a sequence/pattern indication, a timing indication (e.g., periodicity,offset), a sub-band index, a transmission bandwidth, or a transmissionpower. In one example, the notification is received via at least one of:radio resource control signaling, preconfiguration signaling, orapplication layer signaling. In one example, the notification isreceived via out-of-band signaling. For example, a first portion of thebase station may comprise 3GPP 5G infrastructure and a second portion ofthe base station comprises 3G, 4G, or 4G/LTE infrastructure. Inaddition, the channel sounding of the method 200 may be with respect toa 5G channel using the first portion of the base station. In such case,the out-of-band signaling may be using the second portion of the basestation (e.g., 3G, 4G, or 4G/LTE infrastructure). The use of theprevious generation cellular infrastructure (e.g., LTE) for signalingextends the measurement range beyond what would typically be used tosupport user data per 5G (e.g., millimeter wave frequencies for fixedwireless broadband (FWB) for example. In one example, the out-of-bandsignaling could also be through Wi-Fi or WiMAX (if the base station andchannel sounding receiver are both so equipped).

At optional step 220, the processing system may transmitcharacterization parameters of the channel sounding waveform. Thecharacterization parameters may comprise the same or similarcharacterization parameters as mentioned above in connection withoptional step 210, such as at least one of: a sequence/patternindication, a timing indication (e.g., periodicity, offset), a sub-bandindex, a transmission bandwidth, a transmission power, and so forth. Thecharacterization parameters may be transmitted via radio resourcecontrol signaling, preconfiguration signaling, or application layersignaling. In one example, the characterization parameters may betransmitted via out-of-band signaling.

At step 230, the processing system selects a blank resource of a timeand frequency resource grid of the base station for a transmission of achannel sounding waveform. In one example, the selecting is performed inresponse to the receiving the notification of the presence of thechannel sounding receiver that is ready to measure the channel property.In one example, the blank resource comprises at least one time/frequencyresource block that is reserved for forward compatibility or for legacysystem usage within the time and frequency resource grid of the basestation. In one example, the time/frequency resource block that isreserved for forward compatibility is not assigned to user data, controland signaling communications, or the like. Similarly, in one example,the time/frequency resource block that is reserved for legacy systemusage may no longer be in use for legacy system(s), but is not currentlyassigned to user data, control and signaling communications, or thelike. In one example, endpoint devices (e.g., user equipment (UE)) maybe configured to avoid searching for control signals and communicationsin the time/frequency resource blocks that are designated as blankresources, to avoid requesting uplink or downlink reserved resources inthe time/frequency resource blocks that are designated as blankresources, and so forth.

At optional step 240, the processing system may transmit anidentification of the blank resource. The identification of the blankresource may be provided via radio resource control signaling,preconfiguration signaling, or application layer signaling. In oneexample, the identification of the blank resource may be transmitted viaout-of-band signaling. The identification may be in any format whichpositively identifies the correct time-frequency resource block(s) ofthe time and frequency resource grid of the base station that comprisethe blank resources on which the channel sounding waveform is to betransmitted. For instance, in one example, the identification may be ina form according to the specification of the considered wirelesscellular communications standard (e.g., 3GPP 5G).

At step 250, the processing system transmits the channel soundingwaveform via the blank resource. In one example, the selecting of step230 and the transmitting of step 250 are performed in response to thereceiving the notification of the presence of the channel soundingreceiver that is ready to measure the channel property. In one example,when the channel sounding waveform is transmitted, the channel soundingwaveform is non-aligned to the time and frequency resource grid. Forinstance, the transmission can disregard sub-carrier spacing, typicalcyclic prefix(es), timing alignments, symbol length, etc. In oneexample, the channel sounding waveform comprises a Zadoff-Chu (ZC)sequence. In one example, the transmitting the channel sounding waveformcomprises inserting the channel sounding waveform before an inverse fastFourier transform stage of the base station.

At optional step 260, the processing system may receive, from thechannel sounding receiver, an identification of a location of thechannel sounding receiver and a channel property that is based upon thechannel sounding waveform. For instance, the channel propertymeasurement is associated with a location of the channel soundingreceiver. In one example, the channel sounding receiver measures thechannel property based upon the characterization parameters and thechannel sounding waveform that is received. Various channel propertiesas described above may be measured by the channel sounding receiver andprovided to the processing system at optional step 260. In one example,the channel sounding receiver may determine the location using a globalposition system (GPS) component that is attached to or deployed inwithin the channel sounding receiver. Alternatively, or in addition, thechannel sounding receiver may determine the location using base stationtriangulation techniques, such as measuring time of arrival (ToA) ofreference signals from different base stations, and so forth.

At optional step 270, the processing system may determine whether thelocation is a candidate for a deployment of a customer premisesequipment (CPE) based upon the channel property at the location. Forinstance, the processing system may gather channel property measurementsfor various orientations of the channel sounding receiver at thelocation, from a variety of different locations within communicationrange of the base station, and so forth. Using these various channelproperty measurements, the processing system may therefore identifycandidate locations (and/or orientations with respect to the alignmentwith one or more receive beams from base station) for deployment of aCPE. In one example, the CPE may comprise a receiver and/or transceiverfor fixed mobile broadband (FMB) for example. In one example, theprocessing system may determine that the location is a candidate fordeployment of a CPE if the channel property measurements meet apredetermined criteria (e.g., a threshold measured value of the channelproperty, a threshold score that accounts for the channel property andone or more additional channel properties), and so forth. In anotherexample, the processing system may determine that the location is acandidate for deployment of a CPE if the channel property measurementsindicate that the location is one of a top several locations forproviding a best signal quality, a highest throughput, or the like ascompared to other locations within communication range of the basestation.

Following step 250, optional step 260, and/or optional step 270, themethod 200 proceeds to step 295 where the method ends.

FIG. 3 illustrates a flowchart of an example method 300 for channelsounding via an in-service base station, in accordance with the presentdisclosure. In one example, steps, functions and/or operations of themethod 300 may be performed by a device as illustrated in FIG. 1, e.g.,a channel sounding receiver, a mobile endpoint device, and/or a UE, orany one or more components thereof, such as a processing system, a USBcellular dongle, a Global Positioning System (GPS) unit, an antennaarray, and so forth. In one example, the steps, functions, or operationsof method 300 may be performed by a computing device or system 900,and/or a processing system 902 as described in connection with FIG. 9below. For instance, the computing device 900 may represent at least aportion of a channel sounding receiver in accordance with the presentdisclosure. For illustrative purposes, the method 300 is described ingreater detail below in connection with an example performed by aprocessing system, such as processing system 902. The method 300 beginsin step 305 and may proceed to any of optional steps 310-330, or to step340.

At optional step 310, the processing system (e.g., of a channel soundingreceiver) may transmit to a base station, a notification that thechannel sounding receiver is ready to measure a channel property. Thenotification may include an instruction to transmit a channel soundingwaveform via a blank resource. In one example, the instruction mayfurther include characterization parameters of the channel soundingwaveform. The characterization parameters may comprise the same orsimilar characterization parameters as mentioned above in connectionwith optional steps 210 of the example method 200. In one example, thenotification is sent via at least one of: radio resource controlsignaling, preconfiguration signaling, or application layer signaling.In one example, the notification is sent via out-of-band signaling. Forinstance, the sending of the notification may be the same or similar tothat which is described above in connection with optional step 210 ofthe example method 200.

At optional step 320, the processing system may receive anidentification of the blank resource from the base station. Theidentification of the blank resource may be provided via radio resourcecontrol signaling, preconfiguration signaling, application layersignaling, and/or out-of-band signaling. The identification may be inany format which positively identifies the correct time-frequencyresource block(s) of the time and frequency resource grid of the basestation that comprise the blank resources on which the channel soundingwaveform is to be transmitted. The receiving of the identification ofthe blank resource may be from the base station, which may transmit theidentification of the blank resource in the same or a similar manner asdescribed above in connection with step 240 of the example method 200.

At optional step 330, the processing system may receive characterizationparameters of the channel sounding waveform. For instance, theprocessing system may use the characterization parameters in comparisonto a received channel sounding waveform to determine one or more channelproperties, e.g., at the following steps 340 and 350. Thecharacterization parameters may be received (e.g., from the basestation) in the same or a similar manner as the identification of theblank resource that may be received at optional step 320. In oneexample, the identification of the blank resource and thecharacterization parameters may be received in a same communication fromthe base station.

At step 340, the processing system receives, from the base station, at alocation, a channel sounding waveform via the blank resource of the timeand frequency resource grid of the base station. In one example, theprocessing system may tune an antenna receiver system to receive thechannel sounding waveform via a predetermined pattern. For instance, theprocessing system may align a receiver with the frequency sub-carrier(s)at the time(s) corresponding to the blank resource(s), may steer areceiver gain pattern, and so forth.

At step 350, the processing system measures the channel property at thelocation based upon the channel sounding waveform that is received (andin one example, further based upon the characterization parameters).Various channel properties as described above may be measured by thechannel sounding receiver. In one example, the channel sounding receivermay determine the location using a GPS component, using base stationtriangulation techniques, such as measuring time of arrival (ToA) ofreference signals from different base stations, and so forth. In oneexample, the channel sounding receiver may also associate a channelproperty measurement with a particular orientation. For instance, thechannel sounding receiver may include a gyroscope and compass, or thelike, and may determine a particular orientation of a multi-path signal,may determine a direction of a maximum received signal strength, and soforth. The channel property may be associated with various layers of thereceiver protocol stack. For instance, in one example, the channelproperty may be associated with the physical layer and does not requirethat the receiver decipher any particular bit pattern of the channelsounding waveform.

At optional step 360, the processing system may determine whether thelocation is a candidate for a deployment of a customer premisesequipment based upon the channel property at the location. For instance,optional step 360 may comprise the same or similar operations asdescribed above in connection with optional step 270 of the examplemethod 200. In this case, however, the determination may be performed atthe processing system of the channel sounding receiver.

At optional step 370, the processing system may transmit the channelproperty and an identification of the location to the base station. Forinstance, optional step 370 may comprise an alternative to optional step360, where the system includes base station and/or network basedprocessing of channel properties at various locations and/ororientations (e.g., to determine candidate locations and/or orientationsof customer premises equipment).

Following step 350, optional step 360, and/or optional step 370, themethod 300 proceeds to step 395 where the method ends.

FIG. 4 illustrates a flowchart of an example method 400 for channelsounding via an in-service base station, in accordance with the presentdisclosure. In one example, steps, functions and/or operations of themethod 400 may be performed by a device as illustrated in FIG. 1, e.g.,a channel sounding receiver, a mobile endpoint device, and/or a UE, orany one or more components thereof. In one example, the steps,functions, or operations of method 400 may be performed by a computingdevice or system 900, and/or a processing system 902 as described inconnection with FIG. 9 below. For instance, the computing device 900 mayrepresent at least a portion of a channel sounding receiver inaccordance with the present disclosure. For illustrative purposes, themethod 400 is described in greater detail below in connection with anexample performed by a processing system, such as processing system 902.The method 400 begins in step 405 and proceeds to step 410.

At step 410, the processing system detects a synchronization signalwithin a time and frequency resource grid of a base station. Forexample, the synchronization signal may comprise: a primarysynchronization signal, a secondary synchronization signal, or aphysical broadcast channel (PBCH). It should be noted that the PBCH maybe considered a “synchronization signal” in accordance with the presentdisclosure since, in one example, the PBCH can be part of the SS block.In one example, the detecting may comprise blind detection during aninitial access procedure by the channel sounding receiver. It should benoted that this example does not require any changes to the basestation. In other examples, the detecting may be via an explicitindication from the base station via higher layer signaling, e.g., RRC,by preconfiguration, or by out-of-band communication.

At step 420, the processing system measures a channel property at thefirst location based upon the synchronization signal that is received atthe first location. In one example, step 410 may include receivingmultiple synchronization signals, and step 420 may correspondinglyinclude measuring the channel property for multiple synchronizationsignals. In addition, the receiving and measuring may be performed overmultiple SS bursts (e.g., for as many bursts as the channel soundingreceiver selects, for as many antenna ports as the channel soundingreceiver wants to obtain measurements, for as many SS sweeps of the basestation as the channel sounding receiver is configured or programmed towait for, and so on).

At step 425, the processing system receives, at a second location, thesynchronization signal from the base station. Step 425 may comprise thesame or similar operations as step 410, albeit with respect to thesecond location.

At step 430, the processing system measures the channel property at thesecond location based upon the synchronization signal that is receivedat the second location. Step 430 may comprise the same or similaroperations as step 420. In one example, the measuring the channelproperty at the first location per step 420 comprises measuring aplurality of channel properties at the first location, and the measuringthe channel property at the second location per step 430 comprisesmeasuring the plurality of channel properties at the second location.For instance, in one example, the plurality of channel propertiescomprises at least two of: path loss, material loss, angular spread, orDoppler spread. The channel property or properties measured at steps 420and 430 may include a variety of other channel properties as describedherein.

At optional step 435, the processing system may receive, from the basestation by the processing system at the first location, a referencesignal. The reference signal may comprise, for example, a positioningreference signal (PRS) or a channel state information reference signal(CSI-RS).

At optional step 440, the processing system may measure an additionalchannel property at the first location based upon the reference signalthat is received at the first location. In one example, step 440 mayalso include receiving multiple reference signals and measuring one ormore channel properties based upon the multiple reference signals.

At optional step 445, the processing system may receive, from the basestation by the processing system at the second location, the referencesignal. It should be noted that the reference signal received atoptional step 445 may comprise a different base station transmission ata different time as the reference signal received at optional step 335.However, the reference signal may have the same properties (e.g., thesame characterization parameters) as the reference signal received atoptional step 435. Hence, with respect to optional step 445 it isreferred to as the same reference signal. Similarly, optional step 445may comprise receiving multiple reference signals at the secondlocation.

At optional step 450, the processing system may measure the additionalchannel property at the second location based upon the reference signalthat is received at the second location. It should be noted that theadditional channel property that is measured at optional step 450 is thesame “additional channel property” that is measured at optional step440.

At step 455, the processing system selects between the first locationand the second location for a deployment of a customer premisesequipment based upon the channel property at the first location and thechannel property at the second location. In one example, the selectingbetween the first location and the second location for the deployment ofthe customer premises equipment is based upon the plurality of channelproperties at the first location and the plurality of channel propertiesat the second location. In one example, the selecting between the firstlocation and the second location for the deployment of the customerpremises equipment is further based upon the additional channel propertyat the first location and the additional channel property at the secondlocation (e.g., that are measured at optional steps 440 and 450 withrespect to the reference signal). In one example, step 455 may comprisesimilar operations to that which is described above in connection withoptional step 360 of the example method 300.

Following step 455, the method 400 proceeds to step 495 where the methodends.

FIG. 5 illustrates a flowchart of an example method 500 for channelsounding via an in-service base station, in accordance with the presentdisclosure. In one example, steps, functions and/or operations of themethod 500 may be performed by a device as illustrated in FIG. 1, e.g.,a channel sounding receiver, a mobile endpoint device, and/or a UE, orany one or more components thereof. In one example, the steps,functions, or operations of method 500 may be performed by a computingdevice or system 900, and/or a processing system 902 as described inconnection with FIG. 9 below. For instance, the computing device 900 mayrepresent at least a portion of a channel sounding receiver inaccordance with the present disclosure. For illustrative purposes, themethod 500 is described in greater detail below in connection with anexample performed by a processing system, such as processing system 902.The method 500 begins in step 505 and proceeds to step 510.

At step 510, a processing system (e.g., of a channel sounding receiver)detects a reference signal within a time and frequency resource grid ofa base station. The reference signal may comprise, for example, apositioning reference signal (PRS) or a channel state informationreference signal (CSI-RS). In one example, the detecting may compriseblind detection during an initial access procedure by the channelsounding receiver. It should be noted that this example does not requireany changes to the base station. In other examples, the detecting may bevia an explicit indication from the base station via higher layersignaling, e.g., RRC, by preconfiguration, or by out-of-bandcommunication.

At step 515, the processing system receives, at a first location fromthe base station, the reference signal. In one example, the processingsystem may receive multiple reference signals at the first location fromthe base station. In one example, steps 510 and/or 515 may comprise thesame or similar operations as described above in connection withoptional step 435 of the example method 400.

At step 520, the processing system measures a channel property at thefirst location based upon the reference signal that is received at thefirst location (or a plurality of channel properties based upon thereference signal, or multiple reference signals). In one example, step520 may comprise the same or similar operations as described above inconnection with optional step 440 of the example method 400.

At step 525, the processing system receives, at a second location fromthe base station, the reference signal. Step 525 may comprise the sameor similar operations as step 515, albeit with respect to the secondlocation.

At step 530, the processing system measures the channel property at thesecond location based upon the reference signal(s) that is/are receivedat the second location. Step 530 may comprise the same or similaroperations as step 520, albeit with respect to the second location.

At optional step 535, the processing system may receive at the firstlocation from the base station, a synchronization signal of asynchronization signaling block. In one example, optional step 535 maycomprise the same or similar operations as described above in connectionwith step 410 of the example method 400.

At optional step 540, the processing system may measure an additionalchannel property at the first location based upon the synchronizationsignal that is received at the first location. In one example, optionalstep 540 may comprise the same or similar operations as described abovein connection with step 420 of the example method 400.

At optional step 545, the processing system may receive at the secondlocation from the base station, the synchronization signal. Optionalstep 545 may comprise the same or similar operations as step 535, albeitwith respect to the second location.

At optional step 550, the processing system may measure the additionalchannel property at the second location based upon the synchronizationsignal that is received at the second location. Optional step 550 maycomprise the same or similar operations as step 540, albeit with respectto the second location.

At step 555, the processing system selects between the first locationand the second location for a deployment of a customer premisesequipment based upon the channel property at the first location and thechannel property at the second location. In one example, the selectingbetween the first location and the second location for the deployment ofthe customer premises equipment is based upon the plurality of channelproperties at the first location and the plurality of channel propertiesat the second location. In one example, the selecting between the firstlocation and the second location for the deployment of the customerpremises equipment is further based upon the additional channel propertyat the first location and the additional channel property at the secondlocation (e.g., that are measured at optional steps 540 and 550 withrespect to the synchronization signal). In one example, step 555 maycomprise similar operations to that which is described above inconnection with step 455 of the example method 400, and/or optional step360 of the example method 300.

Following step 555, the method 500 proceeds to step 595 where the methodends.

FIG. 6 illustrates a flowchart of an example method 600 for channelsounding via an in-service base station, in accordance with the presentdisclosure. In one example, steps, functions and/or operations of themethod 600 may be performed by a device as illustrated in FIG. 1, e.g.,a base station, or any one or more components thereof. In one example,the steps, functions, or operations of method 600 may be performed by acomputing device or system 900, and/or a processing system 902 asdescribed in connection with FIG. 9 below. For instance, the computingdevice 900 may represent at least a portion of a base station inaccordance with the present disclosure. For illustrative purposes, themethod 600 is described in greater detail below in connection with anexample performed by a processing system, such as processing system 902.The method 600 begins in step 605 and proceeds to step 610.

At step 610, the processing system (e.g., of a base station) transmits achannel state information reference signal (CSI-RS) via a transmit beamthat is selected based upon a transmit beam selection optimization for afirst endpoint device (e.g., a UE). The transmit beam selectionoptimization may be based upon an indication from the first endpointdevice of a preferred transmit beam. In one example, the communicationfrom the first endpoint device may comprise an uplink signalingcommunication in accordance with a beam management procedure defined inthe specification of the considered wireless cellular communicationsstandard (e.g., 3GPP 5G).

At step 620, the processing system receives a notification of a presenceof a channel sounding receiver that is available to perform ameasurement of a channel property. The receiving of the notification atstep 620 may comprise the same or similar operations as described abovein connection with optional step 210 of the example method 200.

At step 630, the processing system transmits, in response to thepresence of the channel sounding receiver, the channel state informationreference signal (CSI-RS) via a beam swept transmission. It should benoted that in accordance with the example method 600, a general mode ofoperation for the base station may comprise transmissions of CSI-RSusing beam selection. However, for purposes of wireless channelsounding, step 630 may comprise changing the base station to a mode ofoperation where CSI-RS is specifically transmitted via beam sweeping.

At optional step 640, the processing system may receive from the channelsounding receiver, an identification of a location of the channelsounding receiver and a channel property measurement that is based uponthe channel state information reference signal (CSI-RS). For example,the channel sounding receiver may measure one or more channel propertiesusing the CSI-RS as a channel sounding waveform. The one or more channelproperties may comprise any of the channel properties described above inconnection with various examples. In one example, a channel propertymeasured at optional step 640 may comprise a multiple-inputmultiple-output (MIMO) measure or a delay spread measure.

At optional step 650 the processing system may determine whether thelocation is a candidate for a deployment of a customer premisesequipment based upon the channel property at the location. For instance,optional step 650 may comprise the same or similar operations asdescribed above in connection with optional step 270 of the examplemethod 200. However, it should be noted that in another example whereoptional steps 640 and 650 are omitted, the channel sounding receivermay measure the channel property based upon the channel stateinformation reference signal and determine whether a location of thechannel sounding receiver is a candidate for a deployment of a customerpremises equipment based upon the channel property at the location. Itshould also be noted that following the channel property measurements inaccordance with the method 600, the processing system may switch thebase station back to a mode of operation where CSI-RS is againtransmitted to endpoint devices (e.g., non-channel sounding UE) via atransmit beam selection optimization procedure.

Following step 630, optional step 640, and/or optional step 650, themethod 600 proceeds to step 695 where the method ends.

FIG. 7 illustrates a flowchart of an example method 700 for channelsounding via an in-service base station, in accordance with the presentdisclosure. In one example, steps, functions and/or operations of themethod 700 may be performed by a device as illustrated in FIG. 1, e.g.,a base station, or any one or more components thereof. In one example,the steps, functions, or operations of method 700 may be performed by acomputing device or system 900, and/or a processing system 902 asdescribed in connection with FIG. 9 below. For instance, the computingdevice 900 may represent at least a portion of a base station inaccordance with the present disclosure. For illustrative purposes, themethod 700 is described in greater detail below in connection with anexample performed by a processing system, such as processing system 902.The method 700 begins in step 705 and may proceed to optional step 710,optional step 720, or step 730.

At optional step 710, the processing system (e.g., of a base station)may receive a notification of a presence of the channel soundingreceiver that is ready to measure the channel property. In one example,the notification comprises an instruction to transmit the channelsounding waveform via the at least one resource block of the physicaldownlink shared channel. In one example, the at least one resource blockcomprises at least one time/frequency resource block of a time andfrequency resource grid implemented at the base station. In one example,the instruction includes characterization parameters of the channelsounding waveform. In one example, the characterization parameters maycomprise at least one of: a resource mapping (which may include aresource block assignment, periodicity, timing, frequency hopping,etc.), a bit sequence, a code rate, a redundancy version, a modulationlevel, a precoding matrix indicator, or a precoder cycling pattern. Thecharacterization parameters can also include a sub-band index, atransmission bandwidth, a transmission power, and so on. In one example,the notification is received via at least one of: radio resource controlsignaling, preconfiguration signaling, or application layer signaling.In one example, the notification is received via out-of-band signaling.Optional step 710 may comprise similar operations to that which isdescribed above in connection with optional step 210 of the examplemethod 200.

At optional step 720, the processing system may transmitcharacterization parameters of the channel sounding waveform. In oneexample, the characterization parameters may comprise the same orsimilar characterization parameters as described above in connectionwith optional step 710. In one example, for the transmitting the channelsounding waveform via the method 700, a modulation coding scheme of thephysical downlink shared channel is set to one of: a binary phase shiftkeying modulation coding scheme, a quadrature phase shift keyingmodulation coding scheme, a modulation coding scheme based upon aprecoding matrix indicator, or a modulation coding scheme based uponprecoder cycling. It should be noted that in one example, a channelsounding process of the method 700 is controlled by the channel soundingreceiver, while in another example, the channel sounding process iscontrolled by the base station processing system. Thus, in one example,characterization parameters, such as a modulation coding scheme, may beselected by the channel sounder receiver and included in thecharacterization parameters of the notification of step 710, or may beselected by the base station processing system and transmitted ascharacterization parameters at optional step 720.

At step 730, the processing system of the base station assigns at leastone resource block of a physical downlink shared channel for atransmission of a channel sounding waveform. As mentioned above, the atleast one resource block may comprise at least one time/frequencyresource block of a time and frequency resource grid implemented at thebase station. In one example, the resource block may be selected by thechannel sounding receiver and included in instructions at optional step710. In such an example, the processing system (of the base station) mayassign the at least one resource block in accordance with theinstruction.

At step 740, the processing system transmits the channel soundingwaveform via the at least one resource block of the physical downlinkshared channel. In the example, the assigning of step 730 and thetransmitting of step 740 are performed in response to the receiving thenotification of the presence of the channel sounding receiver that isready to measure the channel property. In one example, when the channelsounding waveform is transmitted, the channel sounding waveform isaligned to the time and frequency resource grid. In various examples,the transmitting the channel sounding waveform via the physical downlinkshared channel may comprise: setting a payload of a media access controlprotocol data unit to a predetermined bit sequence associated with thechannel sounding waveform, setting a payload of a radio link controlprotocol data unit to a predetermined bit sequence associated with thechannel sounding waveform, or setting a payload of a packet dataconvergence protocol (PDCP) protocol data unit (PDU) to a predeterminedbit sequence associated with the channel sounding waveform.

At optional step 750, the processing system may receive, from thechannel sounding receiver, a channel property that is based upon thechannel sounding waveform and an identification of a location of thechannel sounding receiver. For instance, the channel sounding receivermay measure the channel property based upon the characterizationparameters and the channel sounding waveform that is received. Theobtaining of the measurements and a determination of the location maycomprise the same or similar operations as described above in connectionwith step 350 of the example method 300.

At optional step 760, the processing system may determine whether thelocation is a candidate for a deployment of a customer premisesequipment based upon the channel property at the location. For instance,in one example the channel property is associated with the location ofthe channel sounding receiver. Thus the channel property (or multiplechannel properties) for the location may be compared to channel propertymeasurements for other locations and/or other orientations to determinewhether the location is suitable for deployment of a customer premisesequipment. In one example optional step 760 may comprise the same orsimilar operations as optional step 270 of the example method 200.

Following step 740, optional step 750, or optional step 760, the method700 proceeds to step 795 where the method ends.

FIG. 8 illustrates a flowchart of an example method 800 for channelsounding via an in-service base station, in accordance with the presentdisclosure. In one example, steps, functions and/or operations of themethod 800 may be performed by a device as illustrated in FIG. 1, e.g.,a channel sounding receiver, a mobile endpoint device, and/or a UE, orany one or more components thereof. In one example, the steps,functions, or operations of method 800 may be performed by a computingdevice or system 900, and/or a processing system 902 as described inconnection with FIG. 9 below. For instance, the computing device 900 mayrepresent at least a portion of a channel sounding receiver inaccordance with the present disclosure. For illustrative purposes, themethod 800 is described in greater detail below in connection with anexample performed by a processing system, such as processing system 902.The method 800 begins in step 805 and may proceed to optional step 810,optional step 820, or step 830.

At optional step 810, the processing system (e.g., of a channel soundingreceiver) may transmit to a base station a notification that the channelsounding receiver is ready to measure a channel property. In oneexample, the notification comprises an instruction to transmit thechannel sounding waveform via the at least one resource block of thephysical downlink shared channel. In one example, the at least oneresource block comprises at least one time/frequency resource block of atime and frequency resource grid implemented at the base station. In oneexample, the instruction includes characterization parameters of thechannel sounding waveform. It should be noted that step 810 may comprisethe same or similar operations as described above with respect tooptional step 310 of the example method 300.

At optional step 820, the processing system may receive, from the basestation, characterization parameters of the channel sounding waveform.In one example, the characterization parameters may comprise at leastone of: a resource mapping (which may include a resource blockassignment, periodicity, timing, frequency hopping, etc.), a bitsequence, a code rate, a redundancy version, a modulation level, aprecoding matrix indicator, or a precoder cycling pattern (which canalso include a sub-band index, a transmission bandwidth, a transmissionpower), and so forth.

In one example, for the receiving of the channel sounding waveform viathe method 800, a modulation coding scheme of the physical downlinkshared channel is set to one of: a binary phase shift keying modulationcoding scheme, a quadrature phase shift keying modulation coding scheme,a modulation coding scheme based upon a precoding matrix indicator, or amodulation coding scheme based upon precoder cycling. It should be notedthat in one example, a channel sounding process is controlled by thechannel sounding receiver, while in another example, the channelsounding process is controlled by the base station processing system.Thus, in one example, characterization parameters, such as a modulationcoding scheme, may be selected by the channel sounder receiver andincluded in the characterization parameters of the notification of step810, or may be selected by the base station processing system andreceived as characterization parameters at optional step 820.

At step 830, the processing system receives, from the base station, at alocation, a channel sounding waveform via at least one resource block ofa physical downlink shared channel (PDSCH). In one example, the at leastone resource block comprises at least one time/frequency resource blockof a time and frequency resource grid implemented at the base station.In one example, the channel sounding waveform is aligned to the time andfrequency resource grid of the base station. In various examples, thebase station may transmit the channel sounding waveform via the physicaldownlink shared channel by: setting a payload of a media access controlprotocol data unit to a predetermined bit sequence associated with thechannel sounding waveform, setting a payload of a radio link controlprotocol data unit to a predetermined bit sequence associated with thechannel sounding waveform, or setting a payload of a packet dataconvergence protocol (PDCP) protocol data unit (PDU) to a predeterminedbit sequence associated with the channel sounding waveform.

However, it should be noted that at step 830 the processing system ofthe channel sounding receiver may receive and decode the channelsounding waveform at different layers of the protocol stack, e.g.,depending upon the particular channel property, or channel properties tobe measured. For instance, in one example, step 830 may not include theactual deciphering of the bit sequence. In one example, the channelsounding waveform is received having a modulation coding schemecomprising one of: a binary phase shift keying modulation coding scheme,a quadrature phase shift keying modulation coding scheme, a modulationcoding scheme based upon a precoding matrix indicator, or a modulationcoding scheme based upon precoder cycling. In one example, themodulation coding scheme may be provided as part of the characterizationparameters sent at optional step 810 or received at optional step 820.

At step 840, the processing system measures the channel property at thelocation based upon the channel sounding waveform that is received. Inone example, the measuring of the channel property is further based onthe characterization parameters of the channel sounding waveform (whichmay be sent as part of the notification at optional step 810, orreceived at optional step 820 from the base station). For instance, inone example the measurement of the channel property is associated withthe location of the channel sounding receiver. In one example, step 840may comprise the same or similar operations as described above inconnection with step 350 of the example method 300.

At optional step 850, the processing system may determine whether thelocation is a candidate for a deployment of a customer premisesequipment based upon the channel property at the location. For instance,step 850 may comprise the same or similar operations as described abovein connection with step 360 of the example method 300.

At optional step 860, the processing system may transmit the channelproperty and an identification of the location to the base station. Forinstance, in one example, a channel sounding process according to themethod 800 may be controlled by a base station. In such an example, thechannel sounding receiver may receive the channel sounding waveform andmeasure the channel property or properties, but the determination ofwhether location is a candidate for a deployment of a customer premisesequipment based upon the channel property at the location may beperformed instead by the base station (or other network-based devices).Thus, optional step 860 may comprise an alternative to optional step850.

Following step 840, optional step 850 or optional step 860, the method800 proceeds to step 895 where the method ends.

It should be noted that any of the methods 200-800 may be expanded toinclude additional steps or may be modified to include additionaloperations with respect to the steps outlined above. For example, therespective methods 200-800 may be repeated through various cycles ofchannel property measurements. In addition, aspects of any one or moreof methods 200-800 may be combined to provide an expanded method. Forinstance, a base station processing system may perform operations inaccordance with the method 200, the method 600, and/or the method 700.Similarly, a processing system of a channel sounding receiver mayperform operations in accordance with the method 300, the method 400,and/or the method 800.

In addition, although not specifically specified, one or more steps,functions or operations of the respective methods 200-800 may include astoring, displaying and/or outputting step as required for a particularapplication. In other words, any data, records, fields, and/orintermediate results discussed in the method can be stored, displayedand/or outputted either on the device executing the method or to anotherdevice, as required for a particular application. Furthermore, steps,blocks, functions or operations in any of FIGS. 2-8 that recite adetermining operation or involve a decision do not necessarily requirethat both branches of the determining operation be practiced. In otherwords, one of the branches of the determining operation can be deemed asan optional step. Furthermore, steps, blocks, functions or operations ofthe above described method(s) can be combined, separated, and/orperformed in a different order from that described above, withoutdeparting from the example examples of the present disclosure.

FIG. 9 depicts a high-level block diagram of a computing device orprocessing system specifically programmed to perform the functionsdescribed herein. As depicted in FIG. 9, the processing system 900comprises one or more hardware processor elements 902 (e.g., a centralprocessing unit (CPU), a microprocessor, or a multi-core processor), amemory 904 (e.g., random access memory (RAM) and/or read only memory(ROM)), a module 905 for channel sounding via an in-service basestation, and various input/output devices 906 (e.g., storage devices,including but not limited to, a tape drive, a floppy drive, a hard diskdrive or a compact disk drive, a receiver, a transmitter, a speaker, adisplay, a speech synthesizer, an output port, an input port and a userinput device (such as a keyboard, a keypad, a mouse, a microphone andthe like)). In accordance with the present disclosure input/outputdevices 906 may also include antenna elements, antenna arrays, remoteradio heads (RRHs), baseband units (BBUs), transceivers, power units,and so forth. Although only one processor element is shown, it should benoted that the computing device may employ a plurality of processorelements. Furthermore, although only one computing device is shown inthe figure, if any one or more of the methods 200-800 as discussed aboveis implemented in a distributed or parallel manner for a particularillustrative example, i.e., the steps of the above methods 200-800,respectively, or each of the entire methods 200-800, respectively, isimplemented across multiple or parallel computing devices, e.g., aprocessing system, then the computing device of this figure is intendedto represent each of those multiple computing devices.

Furthermore, one or more hardware processors can be utilized insupporting a virtualized or shared computing environment. Thevirtualized computing environment may support one or more virtualmachines representing computers, servers, or other computing devices. Insuch virtualized virtual machines, hardware components such as hardwareprocessors and computer-readable storage devices may be virtualized orlogically represented. The hardware processor 902 can also be configuredor programmed to cause other devices to perform one or more operationsas discussed above. In other words, the hardware processor 902 may servethe function of a central controller directing other devices to performthe one or more operations as discussed above.

It should be noted that the present disclosure can be implemented insoftware and/or in a combination of software and hardware, e.g., usingapplication specific integrated circuits (ASIC), a programmable gatearray (PGA) including a Field PGA, or a state machine deployed on ahardware device, a computing device or any other hardware equivalents,e.g., computer readable instructions pertaining to the method discussedabove can be used to configure a hardware processor to perform thesteps, functions and/or operations of the above disclosed methods200-800. In one example, instructions and data for the present module orprocess 905 for channel sounding via an in-service base station (e.g., asoftware program comprising computer-executable instructions) can beloaded into memory 904 and executed by hardware processor element 902 toimplement the steps, functions or operations as discussed above inconnection with the illustrative methods 200-800. Furthermore, when ahardware processor executes instructions to perform “operations,” thiscould include the hardware processor performing the operations directlyand/or facilitating, directing, or cooperating with another hardwaredevice or component (e.g., a co-processor and the like) to perform theoperations.

The processor executing the computer readable or software instructionsrelating to the above described method can be perceived as a programmedprocessor or a specialized processor. As such, the present module 905for channel sounding via an in-service base station (includingassociated data structures) of the present disclosure can be stored on atangible or physical (broadly non-transitory) computer-readable storagedevice or medium, e.g., volatile memory, non-volatile memory, ROMmemory, RAM memory, magnetic or optical drive, device or diskette andthe like. Furthermore, a “tangible” computer-readable storage device ormedium comprises a physical device, a hardware device, or a device thatis discernible by the touch. More specifically, the computer-readablestorage device may comprise any physical devices that provide theability to store information such as data and/or instructions to beaccessed by a processor or a computing device such as a computer or anapplication server.

While various examples have been described above, it should beunderstood that they have been presented by way of illustration only,and not a limitation. Thus, the breadth and scope of any aspect of thepresent disclosure should not be limited by any of the above-describedexamples, but should be defined only in accordance with the followingclaims and their equivalents.

What is claimed is:
 1. A method comprising: selecting, by a processingsystem of a base station, a blank resource of a time and frequencyresource grid of the base station for a transmission of a channelsounding waveform, wherein the blank resource comprises at least onetime-frequency resource block of the time and frequency resource gridthat is reserved for forward compatibility or for legacy system usage;and transmitting, by the processing system, the channel soundingwaveform via the blank resource.
 2. The method of claim 1, furthercomprising: receiving, by the processing system from a channel soundingreceiver, an identification of a location of the channel soundingreceiver and a channel property that is based upon the channel soundingwaveform.
 3. The method of claim 2, further comprising: transmittingcharacterization parameters of the channel sounding waveform.
 4. Themethod of claim 3, wherein the channel sounding receiver measures thechannel property based upon the characterization parameters.
 5. Themethod of claim 3, wherein the characterization parameters comprise atleast one of: a pattern indication; a timing indication; a sub-bandindex; a transmission bandwidth; or a transmission power.
 6. The methodof claim 1, further comprising: transmitting an identification of theblank resource.
 7. The method of claim 1, further comprising: receivinga notification of a presence of a channel sounding receiver that isready to measure a channel property.
 8. The method of claim 7, whereinthe notification comprises an instruction to transmit the channelsounding waveform via the blank resource.
 9. The method of claim 8,wherein the instruction includes characterization parameters of thechannel sounding waveform.
 10. The method of claim 7, wherein theselecting and transmitting are performed in response to the receivingthe notification of the presence of the channel sounding receiver thatis ready to measure the channel property.
 11. The method of claim 7,wherein the notification is received via at least one of: radio resourcecontrol signaling; preconfiguration signaling; application layersignaling; or out-of-band signaling.
 12. The method of claim 1, whereinwhen the channel sounding waveform is transmitted, the channel soundingwaveform is non-aligned to the time and frequency resource grid.
 13. Themethod of claim 1, wherein the transmitting the channel soundingwaveform comprises inserting the channel sounding waveform before aninverse fast Fourier transform stage of the base station.
 14. A basestation comprising: a processing system; and a computer-readable mediumstoring instructions which, when executed by the processing system,cause the processing system to perform operations, the operationscomprising: selecting a blank resource of a time and frequency resourcegrid of the base station for a transmission of a channel soundingwaveform, wherein the blank resource comprises at least onetime-frequency resource block of the time and frequency resource gridthat is reserved for forward compatibility or for legacy system usage;and transmitting the channel sounding waveform via the blank resource.15. A method comprising: receiving, from a base station by a processingsystem of a channel sounding receiver at a location, a channel soundingwaveform via a blank resource of a time and frequency resource grid ofthe base station, wherein the blank resource comprises at least onetime-frequency resource block of the time and frequency resource gridthat is reserved for forward compatibility or for legacy system usage;and measuring, by the processing system, a channel property at thelocation based upon the channel sounding waveform that is received. 16.The method of claim 15, further comprising: receiving an identificationof the blank resource; and receiving characterization parameters of thechannel sounding waveform, wherein the measuring the channel property isfurther based on the characterization parameters of the channel soundingwaveform.
 17. The method of claim 15, further comprising: transmitting,by the processing system to the base station, a notification that thechannel sounding receiver is ready to measure the channel property. 18.The method of claim 17, wherein the notification includes an instructionfor the base station to transmit the channel sounding waveform via theblank resource, wherein the instruction includes characterizationparameters of the channel sounding waveform, and wherein the measuringthe channel property is further based on the characterization parametersof the channel sounding waveform.
 19. The method of claim 15, furthercomprising: determining whether the location is a candidate for adeployment of a customer premises equipment based upon the channelproperty at the location.
 20. The base station of claim 14, theoperations further comprising: receiving, from a channel soundingreceiver, an identification of a location of the channel soundingreceiver and a channel property that is based upon the channel soundingwaveform.